Some scenarios will directly use bare chips, such as COB, or RF microwave high-speed chips and so on. Generally, the outermost layer of the chip has a passivation layer of um level thickness to protect the circuit inside the chip, leaving only the Pad as the interface. Silicon wafers are fragile in several ways.
1. You need a clean environment. Particles of PM2.5 or PM10 or above on the chip will affect performance and reliability.
2. Be careful when operating, the tip of the tweezers is easy to scratch the passivation layer, causing damage to the circuit connections or components inside, and the dirty suction nozzle accidentally breaks tens of thousands of transistors.
(3) ESD, because the parasitic capacitance of the IC transistor is very small, especially the high-speed circuit interface, the release of static electricity on the small capacitor will cause a large voltage, directly damage the interface.
4. The thickness of the chip is generally thin (such as typical 0.15mm), and its mechanical strength can be imagined to be relatively weak.
5. Other factors that cause chip failure or damage. Finally, to use an analogy, a person who pees on an ant's nest is just a pee for a person, but a flood for an ant. Besides, the components and wiring of the integrated phone are much smaller than ants... That should make it clear. Reddish purple
The basic unit of integrated circuit is composed of semiconductor resistor, diode and transistor. These components are made by injecting positive or negative ions onto silicon wafers according to a layout designed by a computer.
The method is to coat the silicon wafer with a layer of protective film, and then remove the protective film of the part that needs to be injected with ions by photolithography, and then inject ions like the silicon wafer, and the non-protective film part is injected with ions to form P junction (groove) or N junction (groove), and then make other cloth parts in a similar way.
With the same photolithography, no part of the wiring is exposed, and then the silicon wafer is steamed with aluminum. After removing the protective film, the original bare leakage cloth is retained by the aluminum directly on the silicon wafer to form a wire.
Or like PCB production, a large area of aluminum is steamed first, and then coated with protective film, lithography, and then the unnecessary part of the ticket is washed off to form a wire.